This invention relates to so-called bypass type electric motor operated vacuum cleaners, and more particularly relates to the construction of a housing assembly for the motor/fan unit that is mounted to the lid of the vacuum cleaner tank.
Many so-called bypass type vacuum cleaners include a tank having a lid forming a removable closure for the top opening of the tank wherein sweepings are collected. This lid also mounts a fan unit, an electric motor for rotating the impeller of the fan unit and a molded insulating casing or housing assembly for the motor and fan unit. Constructions of this type are described in U.S. Pat. No. 4,330,899 issued May 25, 1982 to J. Miller et al for "Noise Reducing Blower Motor Housing Means For Vacuum Cleaner, Or The Like"; U.S. Pat. No. 4,435,877 issued Mar. 13, 1984 to R. C. Berfield for "Noise Reducing Means for Vacuum Cleaner"; and pending U.S. patent application Ser. No. 514,491 filed July 18, 1983 by J. Miller et al for an "Assembly of Tank Lid and Fan Means of a Wet/Dry Vacuum.
In those constructions, the motor housing assembly is provided with internal partitions that separate motor cooling air from the flow of working air generated by the vacuum producing main fan. In addition, housing partitions are provided to define plenums wherein the velocity of working air flow is reduced and noise is dissipated before the working air is discharged from the motor housing.